An often overlooked feature of Google Earth, elevation profiles were first introduced in version 5.2. The feature is easy to use, all you need is a path selected in your ‘My Places’ then go to the ‘Edit’ menu and select ‘Show Elevation Profile’.
If you want the elevation profile of a slice through a mountain or valley, simply draw a straight line using the ‘Add Path’ tool on the Google Earth toolbar. But it is not restricted to straight lines and much more often you will be interested in the elevation profile of a hike you are planning, or bicycle route. In this case, you can draw out the path as before, or if it is a route on roads/paths already marked on Google Earth, you can use the Get Directions feature right-click (CTRL click on Mac) on the blue line and select ‘Show Elevation Profile’.
Elevation profile of a route in the Swiss Alps.
If you hold your mouse over the elevation profile, it will show a red arrow on the map marking the location, and also display the height above sea level and gradient at that point.
Keep in mind that Google Earth’s elevation data is not very high resolution and should not be taken as anything more than a rough guide. We also discovered that on the route shown above there were several tunnels and bridges and the route in Google Earth that is used for the elevation profile follows the ground and not the actual road surface resulting in large bumps and dips in the elevation profile.